Anoher Death Wobble thread

[albee]

What preload did the new knuckle bearings have when you replaced them?


Did you check the preload after installing the new bearings?


Did you do this with the wiper seals on the rear side of the knuckle? If so, your indicated drag is not accurate as you are supposed to check preload on the knuckle bearings with the wiper seals removed.

The FSM states that preload is supposed to be around 4-7# of drag (or something very close to that, I do not have the FSM in front of me right now)...I set them up tighter than that when I go through them, (10-12#) since most that I have done are being used with significantly larger tires than the H78-15's that they came with.



Your toe-in seems a bit much. I would measure it with the wheel on the hub at the leading edge and trailing edge of the tire at the 3 and 9 o’clock position, and try and keep it in the 3/16” to a 1/4" area.


Radial or Bias-ply tires? How long have they been sitting? Have you ran it down the road long enough to get them warm to run the flat spots out?



Thanks!


-Steve

I did not check the preload of the old knuckles. The new knuckle berings were checked with a fish scale before the new felt and seal went on. Drivers side knuckle 4 1/4LBS. Pass side knuckle 4 3/4lbs.

The tires are 4 ply of unknown history. When I got them they were mounted on a 5 lug rim filled with air.


Garth the frame rail was welded, but since it is a new install, no cracks could have developed. Good thought.



Trainrech that is how I discovered that my rear axle shaft was bent. Now that has been upgraded to fine spline shafts from a 75'. Thanks

I will realign it, check the balance on the tires, and drive it for a few miles.

Thanks for the ideas. Albee

 

[F-junker]

I'm in the same D.W. boat and working on it, I can't seem to get Bud to get my tierods finished. I'm getting reading to replace all bushings and shackles, then check the castor.

I too have skycrapper springs, what size bilstein shocks did you use? Are you running a larger shackle length?

 

[82cruiser]

Check the shackles

albee - Make sure your shackles are not loose...at all. I had death wobble to varying degrees for years. I had checked and replaced many things trying to chase it down. The shackles were a little too loose which created enough play in lateral axle movement that any decent sized bump in the road would start the wobble. It would get so bad that I'd have to slow down to almost a stop to get the wobble to stop. Cranked down the shackles a bit and POOF!, no more wobble and it tracks straight...relatively speaking.

Randy

 

[albee]

albee - Make sure your shackles are not loose...at all. I had death wobble to varying degrees for years. I had checked and replaced many things trying to chase it down. The shackles were a little too loose which created enough play in lateral axle movement that any decent sized bump in the road would start the wobble. It would get so bad that I'd have to slow down to almost a stop to get the wobble to stop. Cranked down the shackles a bit and POOF!, no more wobble and it tracks straight...relatively speaking.

Randy

Thanks that is good advice. I took my two front tires and had them spun on a balancer, and the Drivers side was 9oz out of balance and pass was 3.5oz. This is probley the reason for the wobble.

I am going to keep it parked in the shop through the winter, and worry about new tires for my stock rims in the spring. Besides I was just looking for a reason to turn this two year build into a three year one. With any luck I will have it done in time to join you guys on the Fall gathering 07.
Thanks Albee

 

[dustin]

It sounds like youre putting this one to bed for the winter, but I still have some suggestions/ questions-

You need to check with the tires off the ground, but still bolted to the axle- grab the wheel and try shaking it. If theres any play at all, track it down from there (you know this..). If its not the steering knuckles/ arms, then check the spindle nut which holds the hub onto the spindle. If that is tight, are the nuts bolting the spindle to the knuckle tight?

When you tightened your steering arms- did you tighten them down in a criss cross ( X and not N ) pattern? And you tightened them without any weight on them - tires were off the ground.. If not, there could be some misalignment of the arm into the trunion bearings.

you mentioned the trunion bearings didnt have "much" grooving. I think any grooving is a bad thing and I would change them.

If you did not shim your steering arms correctly- that can be an issue. The bearing preload is too much or too little.

If youre tie rods are super bad- you will see it/ notice it when shaking, moving everything with the weight off the axle.

good luck,
Dustin

 

[mrgadget]

I just solved my DW problem...........it was my steering stabilizer, replaced it and it's gone..................good luck, Frank

 

[UpsideDown]

I just solved my DW problem...........it was my steering stabilizer, replaced it and it's gone..................good luck, Frank

I haven't run a steering stabilizer in years and have no death wobbles, so imho, the steering damper is just putting a band-aid on some other potential problem.

I'd be really careful about checking both your caster and toe, as well as making sure all your bearings, tre's and bushings are within spec and that there's no excessive play in your steering column or shafting, or your steering box.

The only experience I have had with a serious death wobble (oh, and was it frightening!) was on my FJ45 and it was related to a bad combination of tires, it started at about 35 to 45 mph and it was not possible to drive the truck once is started... the only sane thing I could do was apply the brakes and limp it home slowly.

~j.

 

[projektdotnet]

if you have P/S you shouldn't need a stabilizer unless you have some really super bad out of balance tires really... I run 33"s an FJ60 steering and I don't run a stabilizer. Will have to report on how my SOA rides when I can but I hope it's a lil better than the 4". I had some wobble issues but not enough to jump me out of lanes with my 4" lift. I think mine was a bad TRE or two and tires that are old and wearing. Good luck

 

[bustanutley]

Drivers side knuckle 4 1/4LBS. Pass side knuckle 4 3/4lbs.

These are pretty low number especially considering these were taken with freshly packed bearings, you have to displace the grease. I preload my trunions between 10-20lbs. I also run 37s and this is a bad place for the wobble to start. These are no high cycle bearings it is ok to make them a little tight the weight of the truck rests on the lower bearing mind you.

 

[VTFJ40]

I just solved my DW problem...........it was my steering stabilizer, replaced it and it's gone..................good luck, Frank

Steering stabilizer cannot cause a death wobble, it can only cover one up.

9 oz of weight is ridiculous on a 33. Something is fawked with your rims or tires.

Good luck.

 

[albee]

It sounds like youre putting this one to bed for the winter, but I still have some suggestions/ questions-

You need to check with the tires off the ground, but still bolted to the axle- grab the wheel and try shaking it. If theres any play at all, track it down from there (you know this..). If its not the steering knuckles/ arms, then check the spindle nut which holds the hub onto the spindle. If that is tight, are the nuts bolting the spindle to the knuckle tight?

When you tightened your steering arms- did you tighten them down in a criss cross ( X and not N ) pattern? And you tightened them without any weight on them - tires were off the ground.. If not, there could be some misalignment of the arm into the trunion bearings.

you mentioned the trunion bearings didnt have "much" grooving. I think any grooving is a bad thing and I would change them.

If you did not shim your steering arms correctly- that can be an issue. The bearing preload is too much or too little.

If youre tie rods are super bad- you will see it/ notice it when shaking, moving everything with the weight off the axle.

good luck,
Dustin

Trunion berings were replaced. Poser asked the condition of the old ones. Bearing pre loads all fall within spec. Tierods and ends are all new.

These are pretty low number especially considering these were taken with freshly packed bearings, you have to displace the grease. I preload my trunions between 10-20lbs. I also run 37s and this is a bad place for the wobble to start. These are no high cycle bearings it is ok to make them a little tight the weight of the truck rests on the lower bearing mind you.

Since I am only running 33s I kept the perloads w/in specs from the FSM. Also the preload was measured before the felts and seals were installed. They added a fair amout of stiffness.

Steering stabilizer cannot cause a death wobble, it can only cover one up.

9 oz of weight is ridiculous on a 33. Something is fawked with your rims or tires.

Good luck.

New tires will be put on in the spring, after my wife has had some time to forget how much $$$$ I spent on cruiser parts this year.

Thanks for all of the great suggestions.
Albee

 

[Pin_Head]

Your toe in is still way off and have you checked the run out on your wheels? Try swapping wheels front to back and see if the problem goes away.

 

[Brian in Oregon]

9 oz of weight is ridiculous on a 33. Something is fawked with your rims or tires.

New tires will be put on in the spring, after my wife has had some time to forget how much $$$$ I spent on cruiser parts this year.

9 oz of weight suggests there is a problem with the balancing.

The tires on my FJ40 were supposed to have been balanced. They had weights on them from when the tires were first installed. However, I had severe death wobble at 55 mph. The shop found that the tires were badly out of balance, and had excessive amounts of wheel weights added. I don't know if the first shop fawked up, or if the PO had aired the tires down and spun them in the rim. But the shop aired down the tires, broke the bead from the rim, rotated the tire positions on the rim, and rebalanced. Less weight was used, and the DW went away.

I suggest giving the tires one more try before replacing them.

Also, don't assume the tires are bad. Are you sure the rims themselves are in balance?

 

[albee]

Your toe in is still way off and have you checked the run out on your wheels? Try swapping wheels front to back and see if the problem goes away.

The toe in has been corrected. I do not know what "run out" is on my wheels?

9 oz of weight suggests there is a problem with the balancing.

The tires on my FJ40 were supposed to have been balanced. They had weights on them from when the tires were first installed. However, I had severe death wobble at 55 mph. The shop found that the tires were badly out of balance, and had excessive amounts of wheel weights added. I don't know if the first shop fawked up, or if the PO had aired the tires down and spun them in the rim. But the shop aired down the tires, broke the bead from the rim, rotated the tire positions on the rim, and rebalanced. Less weight was used, and the DW went away.

I suggest giving the tires one more try before replacing them.

Also, don't assume the tires are bad. Are you sure the rims themselves are in balance?

I had the tires re-balanced to try to correct the problem. It did not work, so I tried the dyno beads to balance. They have not worked either. Having them spun on the rims might be a good idea.

I have spent a couple of years and a ton of $$$ building this cruiser. I think it deserves to roll on a new set of tires for its first drive. Besides I want to use the stock rims and hubcaps, I have all painted and waiting for tires.

 

[dustin]

well, with the front wheels off the ground, if you can grab the wheel and shake it back and forth in an up and down motion- and theres any play in there. its your wheel bearing preload. easy fix. I am doubtful of the tires causing it unless your rims are badly bent. People run unbalanced swampers all the time.

cheers-
Dustin